The present invention relates to adjustable fastening devices for rigidly fastening one member to another member with the members or their anchorage at variable positions with respect to each other, and it relates more particularly to means that utilize a wedging principle to provide a positive fastening means with the members at their various positions.
There are numerous situations in which a means of adjustable support must be provided between two members. For instance, for the attachment of facade panels to building structures, it is common practice to provide such adjustable anchorage. Due to tolerances inherent in the manufacture of panels and in the construction of building frames, variations from the theoretical location of any connecting devices in the panel and the relative position of any anchorage provided on the structure can be expected. Likewise similar means of adjustable support are often used for attachment of other types of facade components to building structures.
Panels are frequently supported on the building frame by means of support angles anchored to the structure directly or through the floor slab by an anchor bolt which projects through a hole in the horizontal leg of the support angle. The panel is attached to the vertical leg by a connecting bolt suitably anchored and projecting from the back of the panel. Additional anchorage and ties are provided as required for lateral support. Adjustments have often been accomplished with various combinations of slots and shims, inserted and removed from between attachment surfaces. Shimming is a sometimes trial-and-error, time consuming process. Slots are not usually considered satisfactory for vertical adjustment, except for the lightest of panels, unless they are provided with an integral wedging device so as to provide positive load support at any position in the slot.
Various wedging devices are widely used, but each has certain limitations which make them impractical for some applications. Many require embedment in concrete of an insert with an integral inclined plane. The wedging mechanism can be located at the vertical leg of the support angle by attaching an inclined surface for engagement with an askew head bolt or a bevel washer, or a special tapered slot can be formed in the angle leg for wedging engagement with a double tapered bushing or nut as disclosed in my prior U.S. Pat. No. 4,021,991. In the one method, the beveled surface device must be prevented from movement relative to the angle by mechanically fastening or more usually by welding. In the other case, equipment not available to some fabricators of support angles is required for forming the tapered slot. Another consideration is that in some instances it is desirable that both horizontal and vertical adjustments in the plane of the panel be made at the bolt connecting the panel to the support angle. Unless a slotted insert can be cast in the panel, such a two-way adjustable connection can only be made with considerable difficulty.
It is accordingly an object of the present invention not only to provide a method for making load supporting, two-way adjustable connections, but also to provide a simpler method for adapting clip angles for wedging type adjustable attachment of one member to another.